I’m about to paint my porch and I’m wondering a few things:
1. There is some dirt that’s built up over the years, I’ve already scraped, sanded and sprayed with a hose but some remains. Do I need to get it all off before I paint? Do I really need to power wash? Would scrubbing with a brush and soap be as good/better (I’d like to avoid the hassle of renting a power washer)?
2. There is some black spotty mold in places; what’s the best way to remove this?
3. Lastly, the old roof leaked (I re-shingles already) so some of the ply wood roof has black mold on it; what’s the best way to remove this?
Thanks, Mischa
Discussion Forum
Discussion Forum
Up Next
Video Shorts
Featured Story
Listeners write in about haunted pipes and building-science tomes, and they ask questions about roof venting and roof leaks.
Featured Video
Highlights
"I have learned so much thanks to the searchable articles on the FHB website. I can confidently say that I expect to be a life-long subscriber." - M.K.
Replies
1) Scrubbing with a brush is better than using a power washer. Not only do you get the floor cleaner, but you also avoid driving water into the wood. And yes, you need to remove all of the dirt otherwise you're just asking for the new paint to peel. Don't confuse stains with dirt. If rubbing with damp clean white cloth leaves the cloth clean, it's a stain and gets painted over.
2) Allow the moldy areas to soak for a little while with a mixture of soap (almost any will do, but I usually use laundry detergent) and bleach. Then scrub, mop, wipe or whatever is appropriate.
3) I dunno.